The Cook Islands seasons at a glance

The southern Cook Islands, including Rarotonga and Aitutaki, have a tropical climate with two broad seasons. Temperatures stay in the mid-20s to around 30°C all year, and sea temperatures remain comfortable for swimming. The table below summarises what to expect.

Month-by-month notes

• January and February: the hottest, most humid months, with frequent heavy showers and the highest cyclone risk. Rates are low once the New Year rush ends, but keep plans flexible.
• March and April: still warm and wet early on, with conditions gradually easing through April. Easter can bring a short spike in visitors from New Zealand.
• May: one of the best-value months. The rains taper off, humidity falls and resorts are relatively quiet before the winter holiday rush.
• June: dry and comfortable, with cooler nights. A strong choice for couples who want dry-season weather before the school holidays begin.
• July and August: the coolest and driest stretch, with lively festivals and busy resorts. Expect breezy days on the water and book well ahead.
• September and October: sunny, calm and warming up again, with whales still around and crowds thinning. Many repeat visitors consider this the ideal window.
• November and December: heat and humidity rise, showers become more frequent, and prices dip until the Christmas holidays push demand back up.

Dry season: May to October

The dry season is the classic time to visit. Humidity drops, days are sunny and evenings can be cool enough for a light layer, particularly in July and August. Trade winds keep conditions comfortable, and visibility for snorkelling is often excellent. This is also when hiking routes such as Rarotonga’s Cross-Island Track are drier and safer underfoot.

The trade-off is demand. July and August overlap with New Zealand and Australian school holidays, which means more families on Rarotonga, fuller flights to Aitutaki and higher accommodation rates. If you want dry-season weather without peak crowds, May, June, September and October are the sweet spots.

• Pack: a light jacket or long-sleeved layer for evenings and windy boat trips.
• Book: resorts and domestic flights several months ahead for July and August.
• Expect: occasional showers and breezy days even in the dry season; the weather is tropical, not desert-like.

Wet season: November to April

From November the air becomes hotter and more humid, and rainfall increases. Showers often arrive as heavy afternoon downpours followed by sunshine rather than days of continuous rain, but there can be longer wet spells. The months of January to March are the hottest and wettest of the year.

This period is also the South Pacific cyclone season. Cyclones do not strike every year, and many visitors travel in these months without problems, but a storm can bring flight disruptions, rough seas and cancelled lagoon cruises. If you book during the wet season, choose flexible rates and travel insurance that covers weather disruption, and monitor forecasts in the days before you fly.

The upside is value. Outside the Christmas and New Year peak, resorts are quieter, rates are lower and you may find upgrades or extra-night deals. Sea temperatures are at their warmest, which suits swimmers and snorkellers.

Crowds, school holidays and prices

Because most visitors come from New Zealand and Australia, school holiday calendars in those countries have a large impact on demand. The busiest periods are typically the July school holidays, the Christmas to mid-January period and Easter. The Te Maeva Nui celebrations around late July and early August also draw extra visitors.

How to find better value

• Travel in shoulder months such as May, June, late September and October for good weather and better rates.
• Avoid school holiday weeks if you are not travelling with children.
• Split your stay between Rarotonga and Aitutaki; Rarotonga has more mid-range options, allowing you to save for a few special nights on Aitutaki.
• Look for packages from New Zealand and Australia, which often bundle flights and accommodation at better prices than booking separately.

Festivals, whales and seasonal highlights

Timing your trip around a seasonal event can add a lot to the experience. The main highlights are:

• Te Maeva Nui (late July to early August): the national celebration marking the anniversary of self-government on 4 August, with dance competitions, drumming, singing and parades on Rarotonga. It is the best time to see Cook Islands performing arts at their most competitive and colourful.
• Humpback whale season (roughly July to October): humpback whales migrate through Cook Islands waters, and sightings from shore or on whale-watching trips are possible, particularly around Rarotonga. Sightings are never guaranteed. If whales are your main goal, compare this with swimming with whales in Tonga.
• Island Nights (all year): dinner shows with traditional dance and drumming run year-round at resorts and cultural venues.
• Christmas and New Year: church services, family gatherings and a festive atmosphere, but also peak demand and higher prices.

Check the official Cook Islands Tourism website for current festival dates, since these can shift slightly from year to year.

The best month for your type of trip

• Honeymoon: September or October, for dry weather, calm lagoons, fewer families and possible whale sightings. See our honeymoon guide for resort ideas, and compare with Bora Bora if you are still choosing a destination.
• Family holiday: July for the most reliable weather and festival atmosphere, or June to avoid the school holiday peak if you can take children out of school.
• Budget trip: November or April, when rates fall but the cyclone peak is not at its height.
• Hiking and outdoor activities: May to September, when trails are drier and temperatures more comfortable.
• Snorkelling and lagoon days: any month can work, but May to October usually offers calmer conditions and clearer water.

Wherever you are travelling from, check entry requirements and travel advisories before you book through official sources such as SafeTravel or Smartraveller. Flight schedules from Auckland and other gateways change by season, so check Air New Zealand and other carriers for your dates.

If you are comparing South Pacific destinations for the same dates, our guides to Fiji and Samoa follow a similar seasonal pattern, so the same advice about the dry season and cyclone months broadly applies.

Packing for each season

Packing light makes island-hopping easier, because domestic flights to Aitutaki have tighter baggage limits than international services. Laundry services are widely available at resorts, so a week’s worth of quick-dry clothing is plenty even for a longer trip.

What you pack depends on when you go. Some items are essential year-round, and some are specific to the season:

• Year-round: reef-safe sunscreen, a hat, sunglasses, a rash vest, water shoes for coral and rocky entries, insect repellent and a reusable water bottle.
• Dry season extras: a light fleece or long-sleeved top for breezy evenings, and a windproof layer for boat trips.
• Wet season extras: a packable rain jacket, quick-dry clothing, a dry bag for phones and cameras, and a little extra flexibility in your schedule.
• For church and villages: modest clothing that covers shoulders and knees, especially for Sunday services.

Frequently Asked Questions